Lifting jack



- Patented Dec. 3l, 1.940

v"IP'A'I'EN'I". OFFICE 2,227,393 LIFTmG JACK f Millard B. Lucker, St. Joseph, Mich., assignor to Auto Specialties Manufacturing Company, St. Ioseph,lMich., a corporation of Michigan Application October 5, 1935, Serial No. 43,752 11 Claims. (Cl. 2514-106) This invention relates to lifting jacks, and more particularly to jacks of-the frictional grip type especially adapted for use with automotive vehicles and the like.-

It is an object of the invention to produce a lifting jack of the friction grip type which provides a relatively large vrange of lifting movement; and t'o produce a jack in which the liftingmember which engages the device to be raised may be readily adjusted as to height and position to facilitate the operative engagement with such device.

A further object of the invention is to provide means for insuring the necessary movements of the actuating clamp under all conditions offoperation, and -for insuring the invariable and rapid gripping action of the holding clamp whereby to preventinadvertent release of the holding clamp and to facilitate even and controlled lowering movement of the lifting member.`

A still further object of the invention is to produce a jack having the above features of construction whichmay be readily produced and assembled, which is durable, and which is reliable and efdcient inoperation.

Other objects and advantages of the invention will appear from the following specication when taken in connection with the accompanying drawing wherein like reference numerals refer to like 3 parts throughout.

In the drawing:

Figure 1 is an elevationalview showing a lifting jack construction embodying the features of the invention.

Figure 2isa`partial longitudinal sectional view taken along the line 2-2 of Figure 3.

Figure 3 is a partial longitudinal sectional view taken along the line 3-3 of Figure 1.

Figure 4 is atransverse section along the line 4-4 of Figure 1.

Figure 5 is a View similarto Figure 2, but shown `ing the parts with the jack operating lever in raisedor actuatedv position.

Figure 6 is a detail perspective of the. holding clamp; and

Figure 7 is a detail perspectiveof the actuating clamp.

'Ihe embodiment of the invention shown in the drawing for purposes of illustrationcomprises a base III having pinned or otherwise suitably fixed thereto an upstanding shaft or standard I I. The j standard II carries the lifting vcasting I2 which is adapted for sliding movement therealong. The casting AI2 has formed at. its upper portion a Aplurality of contact notches I3which are adapted for engagement with the device to. be lifted. In the drawing such device is illustrated as a portion I4 of the bumper of an automotive vehicle as the lifting jack of the present invention is particularly adapted for use in such connection.-

However, it is to be understood that the jack may y be applied as Well to other portions of the vehicle upper surface of the actuating clamp and which passes over a hook 2I formed in the barrel 22 of the'ca'sting I2.- The` spring normally maintains the actuating clamp with its lug 23 in engagement with the housing I2 and with its oppositely disposed portion.24 in engagement with the inner end of the operating lever 25 which is vpivoted at Y 26 to the housing I2. As the operating lever-isactuated, as shown in Figure 5, theactuating clamp is tilted slightly ,upon the standard shaft II to bring its edge portions 28 and 29 into frictional biting engagement with the shaft. The actuating clamp thus becomes locked upon shaft -I I and continued movement of the operating lever 25 produces a lifting of the entire casting I2.'

Upon return movement of the operating lever to the position'shown in Figure 2, the actuating clamp is returned to normal 'position by means of the spring I9. It will be noted that Athe actuating clamp is somewhat S-shap'ed in cross section as seen in Figures 1,' 2 and 5 to lbring its engaging edges 28 and 29 toward a common horizontal plane whereby to facilitate ythe clamping vaction which these edges l'nay make upon the standard shaft. 1 1

The casting I2 is held in the position to which it has been raised by means of the `holding clamp the casting I2. Normally the compression spring retains the gripping edges 36 and 33'1 of the hold ing clamp in continuous lengagenientwith the standard shaft to prevent-any retrograde or downward movement of the lifting casting 2 along the shaft. It will' be noted'particularly, by

reference to Figure 3, that the holding clamp is also somewhat S-shaped in longitudinal crosssection to bring the gripping edges 36 yand 3T toward a commonhorizontal plane to facilitate their gripping action upon the Shaft. The .action of spring 33 combines with any downward force produced upon the portion 3I of the holding clamp by the casting I2 to tilt the clamp upon the shaft and hold the biting edges 36 and 31 in tight engagement therewith to prevent downward displacement of the casting. At the same time the spring permits free upward movement of the holding clamp with the casting I2 so .that the clamp is free to travel upward with the casting as the latter is lifted by means of the actuating clamp and the operating lever 25.

The holding clamp may be conveniently released by the insertion of a release lever 39 between the extending portion 34 of 'the clamp and a depending. projection 40 formed on-the casting I2. As the outer eind 4I of the release lever is moved downwardly as indicated in Figure 1, the portion 34 of the clamp will` be cammed downwardly against the action of spring 33 to release thegripping edges of the clamp from the shaft II. As the clamp is released and the casting I2 moves downwardly, `under the weight of the load carried, the inner end I2 of the release lever mov'es downwardly therewith and thus tends to assume its original relation withrespect to the router end 4I of the lever. By this means the camming action upon portion 34 of the clamp is relieved and the clamp again grips theshaft under the action of compression spring 33. By this means the downward movement of the lifting casting is under accurate control at all times as the casting will only move downwardly as fast as theouter end of the release lever is moved.

In operation after the base I0 has been arranged upon a suitable support, the casting I2 may be lifted bodily and rapidly along the standard Il to bring the "contact portion I3 thereof into engagement with the load to be raised. This free upward movement of the casting is permitted by both the actuating and holding clamps. The casting may be readily rotated upon the shaft to any desired position to facilitate proper engagement with the lo-ad. After the lifting casting has been thus positioned, the operatinglever 25 may be operated to further raise the casting and lift the load. The lever may be moved .through large arcs ofmovement to raise thecasting I2 a substantial increment upon each operation, or the operating lever may be moved through smaller arcs of movement. This permits operation under conditions wherein the range of travel of the operating lever may be limited by reason of some immovable obstruction. As the lifting casting. is raised, it is held against retrograde downward movement by the holding clamp until such time as the release lever 4I is applied, whereupon the downward movement of the casting will be permitted under accurate control.

In the past appreciable difliculty has been encountered with lifting jacks of the friction grip type in securing movement over a suilicient range of lifting travel. By means of the present inveny tion wherein the lifting casting itself carries the gripping clamps and is movable `along a standard' shaft which may be made as long as desired, this difficulty is overcome. The provisionA of the springs I9 and 3 3 for the actuating and holding clamps .insures that the operationsof these mem'- bers will at all times be positive and reliable,

and as'to the latter precludes any possibility that it may not Immediately grip the shaft, thus preventing any possibility of inadvertent release of the jack. h

It is obvious that various modifications may be made in the specificl embodiment of the lnvention shown for the purpose of illustration. Accordingly the invention is not to be limited to the precise construction shown and described, but only as indicated in the following claims.

The invention is hereby claimed vas follows:

1. In a lifting jack, a base, a load actuating member, and'means connecting said member and said base for lifting the member from said base, said means comprising a shaft, a friction clamp adapted to engage the shaft, an operating member for tilting the clamp into gripping engagement with the shaft, and spring means for returning the clamp to normal untilted position and into contact with the load' actuating mem' ber.

2. In a lifting jack, a'base, a load actuating member, and `means connecting said member and said base for lifting the member from the base, said means comprising a shaft, a friction clamp encircling the shaft and adapted to be tilted into gripping engagement therewith, said friction clamp being adapted to engage the load actuating member and having means thereon which positions it in normal untilted position when in engagement with the load actuating member, and

van operating member for tilting the 'clamp into gripping engagement with the shaft.

3. In a lifting jack, a base, an upstanding shaft operatively carried by the base, a load lifting 'memben means for frictionally gripping the vmember to thesh'aft, said means comprising a pair of friction gripping devices, one of which forms a part of means to move the member along the shaft and the other of -which is adapted to hold the member against retrograde movement upon the shaft, vmeans for actuating the moving device through variable increments of movement, a spring for urging the holding device to holding position, and means for overcoming the action of the spring to release said holding device, said last named means comprising a laterally extending projectionon the holding deviceand a cooperating abutment means on the load lifting member, said projection and abutment means being arranged in operative juxtaposition on the same side of the load lifting member to receive an operating bar therebetween.

means comprising a lever pivoted to the lifting housing 'for moving the actuating clamp'relat-ive to the housing while in frictional engagement with the shaft, means causing the actuating clamp to reside in normal untilted position in engagement withA positioning means within the housing, a holding clamp also mounted within the housing and adapted to frictionally embrace the shaft, a spring for normally urging the holding clamp into clamping position, and means for releasing the holding clamp from holding position. i

5. A lifting'jack comprising a base, a. relatively smooth upright shaft operatively carried by the base, an elongated loadlifting member having a load supporting portion at the upper end thereof, said load supporting portion being arranged a substantial distance above the central portion of the load lifting' member and comprising an extension substantially embracing the shaft, said shaft being adapted to pass completely through and extend substantially -above said load lifting member, a friction clamp adapted to'engage the shaft, said clamp bengretained normally against positioning means associated with the load lifting member in non-'tilted position, and ain-operating member for tilting the clamp into gripping engagement with the shaft, said load supporting portion being movable to a position below or above the end of the shaft.

6. In a lifting jack, a base, a load actuating member, means connectingsaid member and said base for lifting the member from the base, said means comprising a shaft, a frictionclamp encircling the shaft and adapted to be tilted into gripping engagement therewith, said friction clamp being adapted to be brought into engagement with the load actuating member, means normally positioning the clamp in untilted position when in engagement with the load actuating member, and an operating member pivotally mounted with respect to the load actuating member and having a friction collar clamp for tilting the clamp into gripping engagement with the shaft and for lifting said pivot and said actuating member bodily from the friction clamp as a fulcrumwhen the clamp is tilted into said shaft grippingengagement.

7.. 'A lifting jack as dened in claim 1, wherein the operating member for tilting the clamp into gripping engagement with the shaft comprises a lever pivotally -mounted on the load actuating member and engageable with the clamp.

8. In a lifting jack, a bas, a load actuating member, and means connectingI said member and said base for lifting the member from the base, said means comprising a shaft, a rst friction portion adapted to engage the clamp adapted to engage the shaft, ari-operating member pivotally carried by the load actuating member for tilting said clamp into gripping engagement with the shaft, spring means for returning the clamp to normal untilted position and into contact with positioning means asso ciated with the load actuated member a second clamp, and spring means engageable with said second clamp for tilting lit into gripping engage- `ment with the shaft.

9. In a lifting jack, a base, an npstanding shaft operatively carried by the base, a load actuating device longitudinally slidable on the shaft comprising a load engaging member and a housing assembly, and means for moving the load actuating device along the shaft relative to the base comprising a rst friction clamp adapted to engage the shaft, an operating lever pivotally mounted on the housing assembly and engageable with the clamp for tilting it into gripping engagement with the shaft, spring means for returning the clamp to untilted position and into contact with positioning means associated with the housing assembly, 'a second clamp adapted to engage the shaft, spring means for tilting said 95 second clamp into gripping engagement with the shaft, and means for releasing the action of said last named spring means.

l0. A lifting jack as Vdefined in claim 9, wherein the load actuating device is of elongated construction longitudinally of the shaft and wherein the load engaging member constitutes va laterally extending automobile bumper contacting.

ing member and also engageable with the moving device for controlling its movements.

MILLARD B. LUCKER.

CERTIFIcAm op comentan. Patent Ne. 2,227,595., i 'December 51, 19m.

MILLARD B. Imm. It :Ls: Ahereby certified that error appears in the printed' specification 'of the above nmnbered patent equring' correction as follow's: Page 5, first-.

colum, line 30, cla-1m 6, strike ont tho word "co1 1ar"; 4and that the said Letters .Patent shou1d`be"`raa d wth this core'cton thereinthat the same may conform to the record of the case" in the Patent Office. I

Signed andsealed this 25t1'1Ivday of- February, A. D.- 19

Henry Van-Arsdale, ($88.1) Acting .Coimnssioner of Patents.4 

